﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

using MakeIT.Deo.Negocios;
using System.IO;

namespace MakeIT.Deo.Apresentacao
{
    public class Util
    {

        /// <summary>
        /// Define o texto de query string que será usado para passar o nome do relatório
        /// </summary>
        public const string CONST_QUERY_STRING_REPORT_NAME = "reportName";

        public static void WindowOpen(Page pagina, string nomeRelatorio)
        {

            string paginaParaAbrir = "window.open('ExibeRelatorio.aspx?" + CONST_QUERY_STRING_REPORT_NAME + "=" + nomeRelatorio + "', 'ExibeRelatorio','menubar=yes,width=700,height=600,toolbar=no,resizable=yes')";

            ScriptManager.RegisterStartupScript(pagina, pagina.GetType(), "window" + "_" + pagina.ClientID, paginaParaAbrir, true);

        }

        public static void ExibeAlert(Page page, string msg)
        {
            //AjaxScriptManager.RegisterStartupScript(page, page.GetType(), "alert" + "_" + page.ClientID, "alert('" + msg + "')", true);

            ScriptManager.RegisterStartupScript(page, page.GetType(), "alert" + "_" + page.ClientID, "alert('" + msg + "');", true);
        }

        //Metodo para limpar formulario
        public static void LimparCampos(Control pnCad)
        {

            foreach (Control ctrl in pnCad.Controls)
            {
                if (ctrl is TextBox)
                {
                    TextBox controleLimpar = (TextBox)ctrl;
                    controleLimpar.Text = string.Empty;
                }
                else if (ctrl is DropDownList)
                {
                    DropDownList controleLimpar = (DropDownList)ctrl;
                    controleLimpar.SelectedIndex = 0;
                }

            }
        }
        public static void HabilitarCampos(bool habilitar, Control controle)
        {

            foreach (Control ctrl in controle.Controls)
            {
                if (ctrl is TextBox || ctrl is CheckBox || ctrl is DropDownList || ctrl is RadioButtonList)
                {
                    ((WebControl)ctrl).Enabled = habilitar;
                }
            }
        }

        public static void logAcesso(string pagina, int? idCategoria, int? idFamilia, int? idSubFamilia, int? idProduto)
        {
            AcessoBO acessoBO = new AcessoBO();
            acessos acessosVO = new acessos();
            acessosVO.Ano = DateTime.Now.Year;
            acessosVO.Dia = DateTime.Now.Day;
            acessosVO.Hora = DateTime.Now.Hour;
            acessosVO.Mes = DateTime.Now.Month;
            acessosVO.Pagina = pagina;
            acessosVO.IdCategoria = idCategoria;
            acessosVO.IdFamilia = idFamilia;
            acessosVO.IdSubFamilia = idSubFamilia;
            acessosVO.IdProduto = idProduto;
            acessosVO.Qtd = 1;
            acessoBO.SalvaAcesso(acessosVO);
        }
        public static void CarregarComboUF(DropDownList comboUF)
        {
            comboUF.Items.Add(new ListItem("Acre", "Acre"));
            comboUF.Items.Add(new ListItem("Alagoas", "Alagoas"));
            comboUF.Items.Add(new ListItem("Amapá", "Amapá"));
            comboUF.Items.Add(new ListItem("Amazonas", "Amazonas"));
            comboUF.Items.Add(new ListItem("Bahia", "Bahia"));
            comboUF.Items.Add(new ListItem("Ceará", "Ceará"));
            comboUF.Items.Add(new ListItem("Espirito Santo", "Espirito Santo"));
            comboUF.Items.Add(new ListItem("Goiás", "Goiás"));
            comboUF.Items.Add(new ListItem("Maranhão", "Maranhão"));
            comboUF.Items.Add(new ListItem("Mato Grosso", "Mato Grosso"));
            comboUF.Items.Add(new ListItem("Mato Grosso do Sul", "Mato Grosso do Sul"));
            comboUF.Items.Add(new ListItem("Minas Gerais", "Minas Gerais"));
            comboUF.Items.Add(new ListItem("Pará", "Pará"));
            comboUF.Items.Add(new ListItem("Paraíba", "Paraíba"));
            comboUF.Items.Add(new ListItem("Paraná", "Paraná"));
            comboUF.Items.Add(new ListItem("Pernambuco", "Pernambuco"));
            comboUF.Items.Add(new ListItem("Piauí", "Piauí"));
            comboUF.Items.Add(new ListItem("Rio de Janeiro", "Rio de Janeiro"));
            comboUF.Items.Add(new ListItem("Rio Grande do Norte", "Rio Grande do Norte"));
            comboUF.Items.Add(new ListItem("Rio Grande do Sul", "Rio Grande do Sul"));
            comboUF.Items.Add(new ListItem("Rondônia", "Rondônia"));
            comboUF.Items.Add(new ListItem("Rorâima", "Rorâima"));
            comboUF.Items.Add(new ListItem("Santa Catarina", "Santa Catarina"));
            comboUF.Items.Add(new ListItem("São Paulo", "São Paulo"));
            comboUF.Items.Add(new ListItem("Sergipe", "Sergipe"));
            comboUF.Items.Add(new ListItem("Tocantins", "Tocantins"));
            comboUF.SelectedValue = "São Paulo";

        }

        public static System.Drawing.Image byteArrayToImage(byte[] byteArrayIn)
        {
            MemoryStream ms = new MemoryStream(byteArrayIn);
            System.Drawing.Image returnImage = System.Drawing.Image.FromStream(ms);
            return returnImage;
        }
        public static byte[] imageToByteArray(System.Drawing.Image imageIn)
        {
            MemoryStream ms = new MemoryStream();
            imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            return ms.ToArray();
        }

        public static System.Drawing.Image FixedSize(System.Drawing.Image imgPhoto, int Width, int Height)
        {
            int sourceWidth = imgPhoto.Width;
            int sourceHeight = imgPhoto.Height;
            int sourceX = 0;
            int sourceY = 0;
            int destX = 0;
            int destY = 0;

            float nPercent = 0;
            float nPercentW = 0;
            float nPercentH = 0;

            nPercentW = ((float)Width / (float)sourceWidth);
            nPercentH = ((float)Height / (float)sourceHeight);
            if (nPercentH < nPercentW)
            {
                nPercent = nPercentH;
                destX = System.Convert.ToInt16((Width -
                              (sourceWidth * nPercent)) / 2);
            }
            else
            {
                nPercent = nPercentW;
                destY = System.Convert.ToInt16((Height -
                              (sourceHeight * nPercent)) / 2);
            }

            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);

            Bitmap bmPhoto = new Bitmap(Width, Height,
                              PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                             imgPhoto.VerticalResolution);

            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.Clear(Color.White);
            grPhoto.InterpolationMode =
                    InterpolationMode.HighQualityBicubic;

            grPhoto.DrawImage(imgPhoto,
                new Rectangle(destX, destY, destWidth, destHeight),
                new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
                GraphicsUnit.Pixel);

            grPhoto.Dispose();
            return bmPhoto;
        }
        public static System.Drawing.Image MaxSize(System.Drawing.Image imgPhoto, int maxWidth, int maxHeight)
        {
            int newWidth = imgPhoto.Width;
            int newHeight = imgPhoto.Height;

            float factor = 0;
            if (newWidth > maxWidth)
            {
                factor = (float)maxWidth / (float)newWidth;
                newWidth = maxWidth;
                newHeight = (int)(newHeight * factor);
            }
            if (newHeight > maxHeight)
            {
                factor = (float)maxHeight / (float)newHeight;
                newWidth = (int)(newWidth * factor);
                newHeight = maxHeight;
            }


            Bitmap bmPhoto = new Bitmap(newWidth, newHeight,
                              PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                             imgPhoto.VerticalResolution);

            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.Clear(Color.White);
            grPhoto.InterpolationMode =
                    InterpolationMode.HighQualityBicubic;

            grPhoto.DrawImage(imgPhoto,
                new Rectangle(0, 0, newWidth, newHeight),
                new Rectangle(0, 0, imgPhoto.Width, imgPhoto.Height),
                GraphicsUnit.Pixel);

            grPhoto.Dispose();
            return bmPhoto;
        }
        public static System.Drawing.Image ScaleByPercent(System.Drawing.Image imgPhoto, int Percent)
        {
            float nPercent = ((float)Percent / 100);

            int sourceWidth = imgPhoto.Width;
            int sourceHeight = imgPhoto.Height;
            int sourceX = 0;
            int sourceY = 0;

            int destX = 0;
            int destY = 0;
            int destWidth = (int)(sourceWidth * nPercent);
            int destHeight = (int)(sourceHeight * nPercent);

            Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb);
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            Graphics grPhoto = Graphics.FromImage(bmPhoto);
            grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;

            grPhoto.DrawImage(imgPhoto,
                new Rectangle(destX, destY, destWidth, destHeight),
                new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
                GraphicsUnit.Pixel);

            grPhoto.Dispose();
            return bmPhoto;
        }
    }



    public class AnimatedGifEncoder
    {
        protected int width; // image size
        protected int height;
        protected Color transparent = Color.Empty; // transparent color if given
        protected int transIndex; // transparent index in color table
        protected int repeat = -1; // no repeat
        protected int delay = 0; // frame delay (hundredths)
        protected bool started = false; // ready to output frames
        //	protected BinaryWriter bw;
        protected MemoryStream fs;

        protected System.Drawing.Image image; // current frame
        protected byte[] pixels; // BGR byte array from frame
        protected byte[] indexedPixels; // converted frame indexed to palette
        protected int colorDepth; // number of bit planes
        protected byte[] colorTab; // RGB palette
        protected bool[] usedEntry = new bool[256]; // active palette entries
        protected int palSize = 7; // color table size (bits-1)
        protected int dispose = -1; // disposal code (-1 = use default)
        protected bool closeStream = false; // close stream when finished
        protected bool firstFrame = true;
        protected bool sizeSet = false; // if false, get size from first frame
        protected int sample = 10; // default sample interval for quantizer

        /**
         * Sets the delay time between each frame, or changes it
         * for subsequent frames (applies to last frame added).
         *
         * @param ms int delay time in milliseconds
         */
        public void SetDelay(int ms)
        {
            delay = (int)Math.Round(ms / 10.0f);
        }

        /**
         * Sets the GIF frame disposal code for the last added frame
         * and any subsequent frames.  Default is 0 if no transparent
         * color has been set, otherwise 2.
         * @param code int disposal code.
         */
        public void SetDispose(int code)
        {
            if (code >= 0)
            {
                dispose = code;
            }
        }

        /**
         * Sets the number of times the set of GIF frames
         * should be played.  Default is 1; 0 means play
         * indefinitely.  Must be invoked before the first
         * image is added.
         *
         * @param iter int number of iterations.
         * @return
         */
        public void SetRepeat(int iter)
        {
            if (iter >= 0)
            {
                repeat = iter;
            }
        }

        /**
         * Sets the transparent color for the last added frame
         * and any subsequent frames.
         * Since all colors are subject to modification
         * in the quantization process, the color in the final
         * palette for each frame closest to the given color
         * becomes the transparent color for that frame.
         * May be set to null to indicate no transparent color.
         *
         * @param c Color to be treated as transparent on display.
         */
        public void SetTransparent(Color c)
        {
            transparent = c;
        }

        /**
         * Adds next GIF frame.  The frame is not written immediately, but is
         * actually deferred until the next frame is received so that timing
         * data can be inserted.  Invoking <code>finish()</code> flushes all
         * frames.  If <code>setSize</code> was not invoked, the size of the
         * first image is used for all subsequent frames.
         *
         * @param im BufferedImage containing frame to write.
         * @return true if successful.
         */
        public bool AddFrame(System.Drawing.Image im)
        {
            if ((im == null) || !started)
            {
                return false;
            }
            bool ok = true;
            try
            {
                if (!sizeSet)
                {
                    // use first frame's size
                    SetSize(im.Width, im.Height);
                }
                image = im;
                GetImagePixels(); // convert to correct format if necessary
                AnalyzePixels(); // build color table & map pixels
                if (firstFrame)
                {
                    WriteLSD(); // logical screen descriptior
                    WritePalette(); // global color table
                    if (repeat >= 0)
                    {
                        // use NS app extension to indicate reps
                        WriteNetscapeExt();
                    }
                }
                WriteGraphicCtrlExt(); // write graphic control extension
                WriteImageDesc(); // image descriptor
                if (!firstFrame)
                {
                    WritePalette(); // local color table
                }
                WritePixels(); // encode and write pixel data
                firstFrame = false;
            }
            catch (IOException e)
            {
                ok = false;
            }

            return ok;
        }

        /**
         * Flushes any pending data and closes output file.
         * If writing to an OutputStream, the stream is not
         * closed.
         */
        public bool Finish()
        {
            if (!started) return false;
            bool ok = true;
            started = false;
            try
            {
                fs.WriteByte(0x3b); // gif trailer
                fs.Flush();
                if (closeStream)
                {
                    fs.Close();
                }
            }
            catch (IOException e)
            {
                ok = false;
            }

            // reset for subsequent use
            transIndex = 0;
            fs = null;
            image = null;
            pixels = null;
            indexedPixels = null;
            colorTab = null;
            closeStream = false;
            firstFrame = true;

            return ok;
        }

        /**
         * Sets frame rate in frames per second.  Equivalent to
         * <code>setDelay(1000/fps)</code>.
         *
         * @param fps float frame rate (frames per second)
         */
        public void SetFrameRate(float fps)
        {
            if (fps != 0f)
            {
                delay = (int)Math.Round(100f / fps);
            }
        }

        /**
         * Sets quality of color quantization (conversion of images
         * to the maximum 256 colors allowed by the GIF specification).
         * Lower values (minimum = 1) produce better colors, but slow
         * processing significantly.  10 is the default, and produces
         * good color mapping at reasonable speeds.  Values greater
         * than 20 do not yield significant improvements in speed.
         *
         * @param quality int greater than 0.
         * @return
         */
        public void SetQuality(int quality)
        {
            if (quality < 1) quality = 1;
            sample = quality;
        }

        /**
         * Sets the GIF frame size.  The default size is the
         * size of the first frame added if this method is
         * not invoked.
         *
         * @param w int frame width.
         * @param h int frame width.
         */
        public void SetSize(int w, int h)
        {
            if (started && !firstFrame) return;
            width = w;
            height = h;
            if (width < 1) width = 320;
            if (height < 1) height = 240;
            sizeSet = true;
        }

        /**
         * Initiates GIF file creation on the given stream.  The stream
         * is not closed automatically.
         *
         * @param os OutputStream on which GIF images are written.
         * @return false if initial write failed.
         */
        public bool Start(MemoryStream os)
        {
            if (os == null) return false;
            bool ok = true;
            closeStream = false;
            fs = os;
            try
            {
                WriteString("GIF89a"); // header
            }
            catch (IOException e)
            {
                ok = false;
            }
            return started = ok;
        }

        /**
         * Initiates writing of a GIF file with the specified name.
         *
         * @param file String containing output file name.
         * @return false if open or initial write failed.
         */
        public bool Start(/*String file*/)
        {
            bool ok = true;
            try
            {
                //			bw = new BinaryWriter( new FileStream( file, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None ) );
                //                fs = new FileStream(file, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None);
                fs = new MemoryStream();
                ok = Start(fs);
                closeStream = true;
            }
            catch (IOException e)
            {
                ok = false;
            }
            return started = ok;
        }

        /**
         * Analyzes image colors and creates color map.
         */
        protected void AnalyzePixels()
        {
            int len = pixels.Length;
            int nPix = len / 3;
            indexedPixels = new byte[nPix];
            NeuQuant nq = new NeuQuant(pixels, len, sample);
            // initialize quantizer
            colorTab = nq.Process(); // create reduced palette
            // convert map from BGR to RGB
            //			for (int i = 0; i < colorTab.Length; i += 3) 
            //			{
            //				byte temp = colorTab[i];
            //				colorTab[i] = colorTab[i + 2];
            //				colorTab[i + 2] = temp;
            //				usedEntry[i / 3] = false;
            //			}
            // map image pixels to new palette
            int k = 0;
            for (int i = 0; i < nPix; i++)
            {
                int index =
                    nq.Map(pixels[k++] & 0xff,
                    pixels[k++] & 0xff,
                    pixels[k++] & 0xff);
                usedEntry[index] = true;
                indexedPixels[i] = (byte)index;
            }
            pixels = null;
            colorDepth = 8;
            palSize = 7;
            // get closest match to transparent color if specified
            if (transparent != Color.Empty)
            {
                transIndex = FindClosest(transparent);
            }
        }

        /**
         * Returns index of palette color closest to c
         *
         */
        protected int FindClosest(Color c)
        {
            if (colorTab == null) return -1;
            int r = c.R;
            int g = c.G;
            int b = c.B;
            int minpos = 0;
            int dmin = 256 * 256 * 256;
            int len = colorTab.Length;
            for (int i = 0; i < len; )
            {
                int dr = r - (colorTab[i++] & 0xff);
                int dg = g - (colorTab[i++] & 0xff);
                int db = b - (colorTab[i] & 0xff);
                int d = dr * dr + dg * dg + db * db;
                int index = i / 3;
                if (usedEntry[index] && (d < dmin))
                {
                    dmin = d;
                    minpos = index;
                }
                i++;
            }
            return minpos;
        }

        /**
         * Extracts image pixels into byte array "pixels"
         */
        protected void GetImagePixels()
        {
            int w = image.Width;
            int h = image.Height;
            //		int type = image.GetType().;
            if ((w != width)
                || (h != height)
                )
            {
                // create new image with right size/format
                System.Drawing.Image temp =
                    new Bitmap(width, height);
                Graphics g = Graphics.FromImage(temp);
                g.DrawImage(image, 0, 0);
                image = temp;
                g.Dispose();
            }
            /*
                ToDo:
                improve performance: use unsafe code 
            */
            pixels = new Byte[3 * image.Width * image.Height];
            int count = 0;
            Bitmap tempBitmap = new Bitmap(image);
            for (int th = 0; th < image.Height; th++)
            {
                for (int tw = 0; tw < image.Width; tw++)
                {
                    Color color = tempBitmap.GetPixel(tw, th);
                    pixels[count] = color.R;
                    count++;
                    pixels[count] = color.G;
                    count++;
                    pixels[count] = color.B;
                    count++;
                }
            }

            //		pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
        }

        /**
         * Writes Graphic Control Extension
         */
        protected void WriteGraphicCtrlExt()
        {
            fs.WriteByte(0x21); // extension introducer
            fs.WriteByte(0xf9); // GCE label
            fs.WriteByte(4); // data block size
            int transp, disp;
            if (transparent == Color.Empty)
            {
                transp = 0;
                disp = 0; // dispose = no action
            }
            else
            {
                transp = 1;
                disp = 2; // force clear if using transparent color
            }
            if (dispose >= 0)
            {
                disp = dispose & 7; // user override
            }
            disp <<= 2;

            // packed fields
            fs.WriteByte(Convert.ToByte(0 | // 1:3 reserved
                disp | // 4:6 disposal
                0 | // 7   user input - 0 = none
                transp)); // 8   transparency flag

            WriteShort(delay); // delay x 1/100 sec
            fs.WriteByte(Convert.ToByte(transIndex)); // transparent color index
            fs.WriteByte(0); // block terminator
        }

        /**
         * Writes Image Descriptor
         */
        protected void WriteImageDesc()
        {
            fs.WriteByte(0x2c); // image separator
            WriteShort(0); // image position x,y = 0,0
            WriteShort(0);
            WriteShort(width); // image size
            WriteShort(height);
            // packed fields
            if (firstFrame)
            {
                // no LCT  - GCT is used for first (or only) frame
                fs.WriteByte(0);
            }
            else
            {
                // specify normal LCT
                fs.WriteByte(Convert.ToByte(0x80 | // 1 local color table  1=yes
                    0 | // 2 interlace - 0=no
                    0 | // 3 sorted - 0=no
                    0 | // 4-5 reserved
                    palSize)); // 6-8 size of color table
            }
        }

        /**
         * Writes Logical Screen Descriptor
         */
        protected void WriteLSD()
        {
            // logical screen size
            WriteShort(width);
            WriteShort(height);
            // packed fields
            fs.WriteByte(Convert.ToByte(0x80 | // 1   : global color table flag = 1 (gct used)
                0x70 | // 2-4 : color resolution = 7
                0x00 | // 5   : gct sort flag = 0
                palSize)); // 6-8 : gct size

            fs.WriteByte(0); // background color index
            fs.WriteByte(0); // pixel aspect ratio - assume 1:1
        }

        /**
         * Writes Netscape application extension to define
         * repeat count.
         */
        protected void WriteNetscapeExt()
        {
            fs.WriteByte(0x21); // extension introducer
            fs.WriteByte(0xff); // app extension label
            fs.WriteByte(11); // block size
            WriteString("NETSCAPE" + "2.0"); // app id + auth code
            fs.WriteByte(3); // sub-block size
            fs.WriteByte(1); // loop sub-block id
            WriteShort(repeat); // loop count (extra iterations, 0=repeat forever)
            fs.WriteByte(0); // block terminator
        }

        /**
         * Writes color table
         */
        protected void WritePalette()
        {
            fs.Write(colorTab, 0, colorTab.Length);
            int n = (3 * 256) - colorTab.Length;
            for (int i = 0; i < n; i++)
            {
                fs.WriteByte(0);
            }
        }

        /**
         * Encodes and writes pixel data
         */
        protected void WritePixels()
        {
            LZWEncoder encoder =
                new LZWEncoder(width, height, indexedPixels, colorDepth);
            encoder.Encode(fs);
        }

        /**
         *    Write 16-bit value to output stream, LSB first
         */
        protected void WriteShort(int value)
        {
            fs.WriteByte(Convert.ToByte(value & 0xff));
            fs.WriteByte(Convert.ToByte((value >> 8) & 0xff));
        }

        /**
         * Writes string to output stream
         */
        protected void WriteString(String s)
        {
            char[] chars = s.ToCharArray();
            for (int i = 0; i < chars.Length; i++)
            {
                fs.WriteByte((byte)chars[i]);
            }
        }

        public MemoryStream getFS()
        {
            return this.fs;
        }
    }



    public class NeuQuant
    {
        protected static readonly int netsize = 256; /* number of colours used */
        /* four primes near 500 - assume no image has a length so large */
        /* that it is divisible by all four primes */
        protected static readonly int prime1 = 499;
        protected static readonly int prime2 = 491;
        protected static readonly int prime3 = 487;
        protected static readonly int prime4 = 503;
        protected static readonly int minpicturebytes = (3 * prime4);
        /* minimum size for input image */
        /* Program Skeleton
           ----------------
           [select samplefac in range 1..30]
           [read image from input file]
           pic = (unsigned char*) malloc(3*width*height);
           initnet(pic,3*width*height,samplefac);
           learn();
           unbiasnet();
           [write output image header, using writecolourmap(f)]
           inxbuild();
           write output image using inxsearch(b,g,r)      */

        /* Network Definitions
           ------------------- */
        protected static readonly int maxnetpos = (netsize - 1);
        protected static readonly int netbiasshift = 4; /* bias for colour values */
        protected static readonly int ncycles = 100; /* no. of learning cycles */

        /* defs for freq and bias */
        protected static readonly int intbiasshift = 16; /* bias for fractions */
        protected static readonly int intbias = (((int)1) << intbiasshift);
        protected static readonly int gammashift = 10; /* gamma = 1024 */
        protected static readonly int gamma = (((int)1) << gammashift);
        protected static readonly int betashift = 10;
        protected static readonly int beta = (intbias >> betashift); /* beta = 1/1024 */
        protected static readonly int betagamma =
            (intbias << (gammashift - betashift));

        /* defs for decreasing radius factor */
        protected static readonly int initrad = (netsize >> 3); /* for 256 cols, radius starts */
        protected static readonly int radiusbiasshift = 6; /* at 32.0 biased by 6 bits */
        protected static readonly int radiusbias = (((int)1) << radiusbiasshift);
        protected static readonly int initradius = (initrad * radiusbias); /* and decreases by a */
        protected static readonly int radiusdec = 30; /* factor of 1/30 each cycle */

        /* defs for decreasing alpha factor */
        protected static readonly int alphabiasshift = 10; /* alpha starts at 1.0 */
        protected static readonly int initalpha = (((int)1) << alphabiasshift);

        protected int alphadec; /* biased by 10 bits */

        /* radbias and alpharadbias used for radpower calculation */
        protected static readonly int radbiasshift = 8;
        protected static readonly int radbias = (((int)1) << radbiasshift);
        protected static readonly int alpharadbshift = (alphabiasshift + radbiasshift);
        protected static readonly int alpharadbias = (((int)1) << alpharadbshift);

        /* Types and Global Variables
        -------------------------- */

        protected byte[] thepicture; /* the input image itself */
        protected int lengthcount; /* lengthcount = H*W*3 */

        protected int samplefac; /* sampling factor 1..30 */

        //   typedef int pixel[4];                /* BGRc */
        protected int[][] network; /* the network itself - [netsize][4] */

        protected int[] netindex = new int[256];
        /* for network lookup - really 256 */

        protected int[] bias = new int[netsize];
        /* bias and freq arrays for learning */
        protected int[] freq = new int[netsize];
        protected int[] radpower = new int[initrad];
        /* radpower for precomputation */

        /* Initialise network in range (0,0,0) to (255,255,255) and set parameters
           ----------------------------------------------------------------------- */
        public NeuQuant(byte[] thepic, int len, int sample)
        {

            int i;
            int[] p;

            thepicture = thepic;
            lengthcount = len;
            samplefac = sample;

            network = new int[netsize][];
            for (i = 0; i < netsize; i++)
            {
                network[i] = new int[4];
                p = network[i];
                p[0] = p[1] = p[2] = (i << (netbiasshift + 8)) / netsize;
                freq[i] = intbias / netsize; /* 1/netsize */
                bias[i] = 0;
            }
        }

        public byte[] ColorMap()
        {
            byte[] map = new byte[3 * netsize];
            int[] index = new int[netsize];
            for (int i = 0; i < netsize; i++)
                index[network[i][3]] = i;
            int k = 0;
            for (int i = 0; i < netsize; i++)
            {
                int j = index[i];
                map[k++] = (byte)(network[j][0]);
                map[k++] = (byte)(network[j][1]);
                map[k++] = (byte)(network[j][2]);
            }
            return map;
        }

        /* Insertion sort of network and building of netindex[0..255] (to do after unbias)
           ------------------------------------------------------------------------------- */
        public void Inxbuild()
        {

            int i, j, smallpos, smallval;
            int[] p;
            int[] q;
            int previouscol, startpos;

            previouscol = 0;
            startpos = 0;
            for (i = 0; i < netsize; i++)
            {
                p = network[i];
                smallpos = i;
                smallval = p[1]; /* index on g */
                /* find smallest in i..netsize-1 */
                for (j = i + 1; j < netsize; j++)
                {
                    q = network[j];
                    if (q[1] < smallval)
                    { /* index on g */
                        smallpos = j;
                        smallval = q[1]; /* index on g */
                    }
                }
                q = network[smallpos];
                /* swap p (i) and q (smallpos) entries */
                if (i != smallpos)
                {
                    j = q[0];
                    q[0] = p[0];
                    p[0] = j;
                    j = q[1];
                    q[1] = p[1];
                    p[1] = j;
                    j = q[2];
                    q[2] = p[2];
                    p[2] = j;
                    j = q[3];
                    q[3] = p[3];
                    p[3] = j;
                }
                /* smallval entry is now in position i */
                if (smallval != previouscol)
                {
                    netindex[previouscol] = (startpos + i) >> 1;
                    for (j = previouscol + 1; j < smallval; j++)
                        netindex[j] = i;
                    previouscol = smallval;
                    startpos = i;
                }
            }
            netindex[previouscol] = (startpos + maxnetpos) >> 1;
            for (j = previouscol + 1; j < 256; j++)
                netindex[j] = maxnetpos; /* really 256 */
        }

        /* Main Learning Loop
           ------------------ */
        public void Learn()
        {

            int i, j, b, g, r;
            int radius, rad, alpha, step, delta, samplepixels;
            byte[] p;
            int pix, lim;

            if (lengthcount < minpicturebytes)
                samplefac = 1;
            alphadec = 30 + ((samplefac - 1) / 3);
            p = thepicture;
            pix = 0;
            lim = lengthcount;
            samplepixels = lengthcount / (3 * samplefac);
            delta = samplepixels / ncycles;
            alpha = initalpha;
            radius = initradius;

            rad = radius >> radiusbiasshift;
            if (rad <= 1)
                rad = 0;
            for (i = 0; i < rad; i++)
                radpower[i] =
                    alpha * (((rad * rad - i * i) * radbias) / (rad * rad));

            //fprintf(stderr,"beginning 1D learning: initial radius=%d\n", rad);

            if (lengthcount < minpicturebytes)
                step = 3;
            else if ((lengthcount % prime1) != 0)
                step = 3 * prime1;
            else
            {
                if ((lengthcount % prime2) != 0)
                    step = 3 * prime2;
                else
                {
                    if ((lengthcount % prime3) != 0)
                        step = 3 * prime3;
                    else
                        step = 3 * prime4;
                }
            }

            i = 0;
            while (i < samplepixels)
            {
                b = (p[pix + 0] & 0xff) << netbiasshift;
                g = (p[pix + 1] & 0xff) << netbiasshift;
                r = (p[pix + 2] & 0xff) << netbiasshift;
                j = Contest(b, g, r);

                Altersingle(alpha, j, b, g, r);
                if (rad != 0)
                    Alterneigh(rad, j, b, g, r); /* alter neighbours */

                pix += step;
                if (pix >= lim)
                    pix -= lengthcount;

                i++;
                if (delta == 0)
                    delta = 1;
                if (i % delta == 0)
                {
                    alpha -= alpha / alphadec;
                    radius -= radius / radiusdec;
                    rad = radius >> radiusbiasshift;
                    if (rad <= 1)
                        rad = 0;
                    for (j = 0; j < rad; j++)
                        radpower[j] =
                            alpha * (((rad * rad - j * j) * radbias) / (rad * rad));
                }
            }
            //fprintf(stderr,"finished 1D learning: readonly alpha=%f !\n",((float)alpha)/initalpha);
        }

        /* Search for BGR values 0..255 (after net is unbiased) and return colour index
           ---------------------------------------------------------------------------- */
        public int Map(int b, int g, int r)
        {

            int i, j, dist, a, bestd;
            int[] p;
            int best;

            bestd = 1000; /* biggest possible dist is 256*3 */
            best = -1;
            i = netindex[g]; /* index on g */
            j = i - 1; /* start at netindex[g] and work outwards */

            while ((i < netsize) || (j >= 0))
            {
                if (i < netsize)
                {
                    p = network[i];
                    dist = p[1] - g; /* inx key */
                    if (dist >= bestd)
                        i = netsize; /* stop iter */
                    else
                    {
                        i++;
                        if (dist < 0)
                            dist = -dist;
                        a = p[0] - b;
                        if (a < 0)
                            a = -a;
                        dist += a;
                        if (dist < bestd)
                        {
                            a = p[2] - r;
                            if (a < 0)
                                a = -a;
                            dist += a;
                            if (dist < bestd)
                            {
                                bestd = dist;
                                best = p[3];
                            }
                        }
                    }
                }
                if (j >= 0)
                {
                    p = network[j];
                    dist = g - p[1]; /* inx key - reverse dif */
                    if (dist >= bestd)
                        j = -1; /* stop iter */
                    else
                    {
                        j--;
                        if (dist < 0)
                            dist = -dist;
                        a = p[0] - b;
                        if (a < 0)
                            a = -a;
                        dist += a;
                        if (dist < bestd)
                        {
                            a = p[2] - r;
                            if (a < 0)
                                a = -a;
                            dist += a;
                            if (dist < bestd)
                            {
                                bestd = dist;
                                best = p[3];
                            }
                        }
                    }
                }
            }
            return (best);
        }
        public byte[] Process()
        {
            Learn();
            Unbiasnet();
            Inxbuild();
            return ColorMap();
        }

        /* Unbias network to give byte values 0..255 and record position i to prepare for sort
           ----------------------------------------------------------------------------------- */
        public void Unbiasnet()
        {

            int i, j;

            for (i = 0; i < netsize; i++)
            {
                network[i][0] >>= netbiasshift;
                network[i][1] >>= netbiasshift;
                network[i][2] >>= netbiasshift;
                network[i][3] = i; /* record colour no */
            }
        }

        /* Move adjacent neurons by precomputed alpha*(1-((i-j)^2/[r]^2)) in radpower[|i-j|]
           --------------------------------------------------------------------------------- */
        protected void Alterneigh(int rad, int i, int b, int g, int r)
        {

            int j, k, lo, hi, a, m;
            int[] p;

            lo = i - rad;
            if (lo < -1)
                lo = -1;
            hi = i + rad;
            if (hi > netsize)
                hi = netsize;

            j = i + 1;
            k = i - 1;
            m = 1;
            while ((j < hi) || (k > lo))
            {
                a = radpower[m++];
                if (j < hi)
                {
                    p = network[j++];
                    try
                    {
                        p[0] -= (a * (p[0] - b)) / alpharadbias;
                        p[1] -= (a * (p[1] - g)) / alpharadbias;
                        p[2] -= (a * (p[2] - r)) / alpharadbias;
                    }
                    catch (Exception e)
                    {
                    } // prevents 1.3 miscompilation
                }
                if (k > lo)
                {
                    p = network[k--];
                    try
                    {
                        p[0] -= (a * (p[0] - b)) / alpharadbias;
                        p[1] -= (a * (p[1] - g)) / alpharadbias;
                        p[2] -= (a * (p[2] - r)) / alpharadbias;
                    }
                    catch (Exception e)
                    {
                    }
                }
            }
        }

        /* Move neuron i towards biased (b,g,r) by factor alpha
           ---------------------------------------------------- */
        protected void Altersingle(int alpha, int i, int b, int g, int r)
        {

            /* alter hit neuron */
            int[] n = network[i];
            n[0] -= (alpha * (n[0] - b)) / initalpha;
            n[1] -= (alpha * (n[1] - g)) / initalpha;
            n[2] -= (alpha * (n[2] - r)) / initalpha;
        }

        /* Search for biased BGR values
           ---------------------------- */
        protected int Contest(int b, int g, int r)
        {

            /* finds closest neuron (min dist) and updates freq */
            /* finds best neuron (min dist-bias) and returns position */
            /* for frequently chosen neurons, freq[i] is high and bias[i] is negative */
            /* bias[i] = gamma*((1/netsize)-freq[i]) */

            int i, dist, a, biasdist, betafreq;
            int bestpos, bestbiaspos, bestd, bestbiasd;
            int[] n;

            bestd = ~(((int)1) << 31);
            bestbiasd = bestd;
            bestpos = -1;
            bestbiaspos = bestpos;

            for (i = 0; i < netsize; i++)
            {
                n = network[i];
                dist = n[0] - b;
                if (dist < 0)
                    dist = -dist;
                a = n[1] - g;
                if (a < 0)
                    a = -a;
                dist += a;
                a = n[2] - r;
                if (a < 0)
                    a = -a;
                dist += a;
                if (dist < bestd)
                {
                    bestd = dist;
                    bestpos = i;
                }
                biasdist = dist - ((bias[i]) >> (intbiasshift - netbiasshift));
                if (biasdist < bestbiasd)
                {
                    bestbiasd = biasdist;
                    bestbiaspos = i;
                }
                betafreq = (freq[i] >> betashift);
                freq[i] -= betafreq;
                bias[i] += (betafreq << gammashift);
            }
            freq[bestpos] += beta;
            bias[bestpos] -= betagamma;
            return (bestbiaspos);
        }
    }




    public class LZWEncoder
    {

        private static readonly int EOF = -1;

        private int imgW, imgH;
        private byte[] pixAry;
        private int initCodeSize;
        private int remaining;
        private int curPixel;

        // GIFCOMPR.C       - GIF Image compression routines
        //
        // Lempel-Ziv compression based on 'compress'.  GIF modifications by
        // David Rowley (mgardi@watdcsu.waterloo.edu)

        // General DEFINEs

        static readonly int BITS = 12;

        static readonly int HSIZE = 5003; // 80% occupancy

        // GIF Image compression - modified 'compress'
        //
        // Based on: compress.c - File compression ala IEEE Computer, June 1984.
        //
        // By Authors:  Spencer W. Thomas      (decvax!harpo!utah-cs!utah-gr!thomas)
        //              Jim McKie              (decvax!mcvax!jim)
        //              Steve Davies           (decvax!vax135!petsd!peora!srd)
        //              Ken Turkowski          (decvax!decwrl!turtlevax!ken)
        //              James A. Woods         (decvax!ihnp4!ames!jaw)
        //              Joe Orost              (decvax!vax135!petsd!joe)

        int n_bits; // number of bits/code
        int maxbits = BITS; // user settable max # bits/code
        int maxcode; // maximum code, given n_bits
        int maxmaxcode = 1 << BITS; // should NEVER generate this code

        int[] htab = new int[HSIZE];
        int[] codetab = new int[HSIZE];

        int hsize = HSIZE; // for dynamic table sizing

        int free_ent = 0; // first unused entry

        // block compression parameters -- after all codes are used up,
        // and compression rate changes, start over.
        bool clear_flg = false;

        // Algorithm:  use open addressing double hashing (no chaining) on the
        // prefix code / next character combination.  We do a variant of Knuth's
        // algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
        // secondary probe.  Here, the modular division first probe is gives way
        // to a faster exclusive-or manipulation.  Also do block compression with
        // an adaptive reset, whereby the code table is cleared when the compression
        // ratio decreases, but after the table fills.  The variable-length output
        // codes are re-sized at this point, and a special CLEAR code is generated
        // for the decompressor.  Late addition:  construct the table according to
        // file size for noticeable speed improvement on small files.  Please direct
        // questions about this implementation to ames!jaw.

        int g_init_bits;

        int ClearCode;
        int EOFCode;

        // output
        //
        // Output the given code.
        // Inputs:
        //      code:   A n_bits-bit integer.  If == -1, then EOF.  This assumes
        //              that n_bits =< wordsize - 1.
        // Outputs:
        //      Outputs code to the file.
        // Assumptions:
        //      Chars are 8 bits long.
        // Algorithm:
        //      Maintain a BITS character long buffer (so that 8 codes will
        // fit in it exactly).  Use the VAX insv instruction to insert each
        // code in turn.  When the buffer fills up empty it and start over.

        int cur_accum = 0;
        int cur_bits = 0;

        int[] masks =
		{
			0x0000,
			0x0001,
			0x0003,
			0x0007,
			0x000F,
			0x001F,
			0x003F,
			0x007F,
			0x00FF,
			0x01FF,
			0x03FF,
			0x07FF,
			0x0FFF,
			0x1FFF,
			0x3FFF,
			0x7FFF,
			0xFFFF };

        // Number of characters so far in this 'packet'
        int a_count;

        // Define the storage for the packet accumulator
        byte[] accum = new byte[256];

        //----------------------------------------------------------------------------
        public LZWEncoder(int width, int height, byte[] pixels, int color_depth)
        {
            imgW = width;
            imgH = height;
            pixAry = pixels;
            initCodeSize = Math.Max(2, color_depth);
        }

        // Add a character to the end of the current packet, and if it is 254
        // characters, flush the packet to disk.
        void Add(byte c, Stream outs)
        {
            accum[a_count++] = c;
            if (a_count >= 254)
                Flush(outs);
        }

        // Clear out the hash table

        // table clear for block compress
        void ClearTable(Stream outs)
        {
            ResetCodeTable(hsize);
            free_ent = ClearCode + 2;
            clear_flg = true;

            Output(ClearCode, outs);
        }

        // reset code table
        void ResetCodeTable(int hsize)
        {
            for (int i = 0; i < hsize; ++i)
                htab[i] = -1;
        }

        void Compress(int init_bits, Stream outs)
        {
            int fcode;
            int i /* = 0 */;
            int c;
            int ent;
            int disp;
            int hsize_reg;
            int hshift;

            // Set up the globals:  g_init_bits - initial number of bits
            g_init_bits = init_bits;

            // Set up the necessary values
            clear_flg = false;
            n_bits = g_init_bits;
            maxcode = MaxCode(n_bits);

            ClearCode = 1 << (init_bits - 1);
            EOFCode = ClearCode + 1;
            free_ent = ClearCode + 2;

            a_count = 0; // clear packet

            ent = NextPixel();

            hshift = 0;
            for (fcode = hsize; fcode < 65536; fcode *= 2)
                ++hshift;
            hshift = 8 - hshift; // set hash code range bound

            hsize_reg = hsize;
            ResetCodeTable(hsize_reg); // clear hash table

            Output(ClearCode, outs);

        outer_loop: while ((c = NextPixel()) != EOF)
            {
                fcode = (c << maxbits) + ent;
                i = (c << hshift) ^ ent; // xor hashing

                if (htab[i] == fcode)
                {
                    ent = codetab[i];
                    continue;
                }
                else if (htab[i] >= 0) // non-empty slot
                {
                    disp = hsize_reg - i; // secondary hash (after G. Knott)
                    if (i == 0)
                        disp = 1;
                    do
                    {
                        if ((i -= disp) < 0)
                            i += hsize_reg;

                        if (htab[i] == fcode)
                        {
                            ent = codetab[i];
                            goto outer_loop;
                        }
                    } while (htab[i] >= 0);
                }
                Output(ent, outs);
                ent = c;
                if (free_ent < maxmaxcode)
                {
                    codetab[i] = free_ent++; // code -> hashtable
                    htab[i] = fcode;
                }
                else
                    ClearTable(outs);
            }
            // Put out the final code.
            Output(ent, outs);
            Output(EOFCode, outs);
        }

        //----------------------------------------------------------------------------
        public void Encode(Stream os)
        {
            os.WriteByte(Convert.ToByte(initCodeSize)); // write "initial code size" byte

            remaining = imgW * imgH; // reset navigation variables
            curPixel = 0;

            Compress(initCodeSize + 1, os); // compress and write the pixel data

            os.WriteByte(0); // write block terminator
        }

        // Flush the packet to disk, and reset the accumulator
        void Flush(Stream outs)
        {
            if (a_count > 0)
            {
                outs.WriteByte(Convert.ToByte(a_count));
                outs.Write(accum, 0, a_count);
                a_count = 0;
            }
        }

        int MaxCode(int n_bits)
        {
            return (1 << n_bits) - 1;
        }

        //----------------------------------------------------------------------------
        // Return the next pixel from the image
        //----------------------------------------------------------------------------
        private int NextPixel()
        {
            if (remaining == 0)
                return EOF;

            --remaining;

            int temp = curPixel + 1;
            if (temp < pixAry.GetUpperBound(0))
            {
                byte pix = pixAry[curPixel++];

                return pix & 0xff;
            }
            return 0xff;
        }

        void Output(int code, Stream outs)
        {
            cur_accum &= masks[cur_bits];

            if (cur_bits > 0)
                cur_accum |= (code << cur_bits);
            else
                cur_accum = code;

            cur_bits += n_bits;

            while (cur_bits >= 8)
            {
                Add((byte)(cur_accum & 0xff), outs);
                cur_accum >>= 8;
                cur_bits -= 8;
            }

            // If the next entry is going to be too big for the code size,
            // then increase it, if possible.
            if (free_ent > maxcode || clear_flg)
            {
                if (clear_flg)
                {
                    maxcode = MaxCode(n_bits = g_init_bits);
                    clear_flg = false;
                }
                else
                {
                    ++n_bits;
                    if (n_bits == maxbits)
                        maxcode = maxmaxcode;
                    else
                        maxcode = MaxCode(n_bits);
                }
            }

            if (code == EOFCode)
            {
                // At EOF, write the rest of the buffer.
                while (cur_bits > 0)
                {
                    Add((byte)(cur_accum & 0xff), outs);
                    cur_accum >>= 8;
                    cur_bits -= 8;
                }

                Flush(outs);
            }
        }
    }


}

